Lubricant coated beverage container or conveyor therefor

Abstract

The passage of a container along a conveyor is lubricated by applying to the container or conveyor a lubricating coating that is thermally cured at less than 200° C. or radiation-cured. The mixture can be applied in relatively low amounts and with relatively low or no water content, to provide thin, substantially non-dripping, renewable lubricating films. In contrast to dilute aqueous lubricants, the lubricants of the invention provide dry lubrication of the conveyors and containers, a cleaner conveyor line and reduced lubricant usage, thereby reducing waste, cleanup and disposal problems.

1. A plastic beverage container whose surface is coated at least in part with a coating that has been thermally cured at less than 200° C. or radiation-cured, whereby the cured coating forms a lubricant layer on the surface of the container. 
     
     
       2. A container according to  claim 1 , wherein the container comprises crystalline and amorphous portions and the cured coating forms a lubricant layer on the surface of one or more of the crystalline portions but not on significant amorphous portions of the container. 
     
     
       3. A container according to  claim 2 , wherein one or more foot portions of a blow-molded, footed polyethylene terephthalate container are coated with the coating. 
     
     
       4. A container according to  claim 1 , wherein the coated surface is UV-cured. 
     
     
       5. A container according to  claim 1 , wherein the coating has a thickness of about 0.001 to about 2 mm. 
     
     
       6. A container according to  claim 1 , wherein the coating comprises a film former selected from urethanes, acrylics, epoxies, melamines and blends or copolymers thereof, together with a lubricant selected from molybdenum disulfide, boron nitride, graphite, silica particles, silicone gums and particles, polytetrafluoroethylene particles, fluoroethylene-propylene copolymers, perfluoroalkoxy resins, ethylene-chlorotrifluoroethylene alternating copolymers, poly (vinylidene fluoride), waxes, fatty acids, phosphate esters and mixtures thereof. 
     
     
       7. A container according to  claim 6 , wherein the coating comprises about 50 to about 97 wt. % film former and about 3 wt. % to about 50 wt. % lubricant. 
     
     
       8. A container according to  claim 6 , wherein the coating comprises about 70 to about 95 wt. % film former and about 5 wt. % to about 30 wt. % lubricant. 
     
     
       9. A container according to  claim 1 , wherein the coating comprised a waterborne UV curable acrylate or urethane or a blend or copolymer thereof, together with a lubricant comprising polytetrafluoroethylene particles. 
     
     
       10. A container according to  claim 1 , wherein the coating has a total alkalinity equivalent to less than about 50 ppm CaCO 3 . 
     
     
       11. A conveyor used to transport beverage containers, having a conveying surface comprising polyacetal coated at least in part with a coating that has been thermally cured or radiation-cured, whereby the coating forms a lubricant layer on the conveyor. 
     
     
       12. A conveyor according to  claim 11 , wherein the coating comprises a film former selected from urethanes, acrylics, epoxies, melamines and blends or copolymers thereof, together with a lubricant selected from molybdenum disulfide, boron nitride, graphite, silica particles, silicone gums and particles, polytetrafluoroethylene particles, fluoroethylene-propylene copolymers, perfluoroalkoxy resins, ethylene-chlorotrifluoroethylene alternating copolymers, poly (vinylidene fluoride), waxes, fatty acids, phosphate esters and mixtures thereof. 
     
     
       13. A conveyor according to  claim 11 , wherein the coating has been thermally cured at less than 120° C. 
     
     
       14. A thermal or radiation curable conveyor lubricating composition comprising a film former that can be thermally cured at less than 200° C. or radiation-cured, a thermal initiator or photoinitiator, and more than 5 weight percent of lubricating fluoropolymer particles. 
     
     
       15. A composition according to  claim 14 , comprising about 50 up to about 95 wt. % film former and up to about 50 wt. % fluoropolymer particles. 
     
     
       16. A composition according to  claim 14 , comprising about 70 to about 95 wt. % film former and up to about 30 wt. % fluoropolymer particles. 
     
     
       17. A composition according to  claim 14 , wherein the film former comprises a waterborne UV curable acrylate or urethane or a blend or copolymer thereof. 
     
     
       18. A conveyor according to  claim 11 , wherein the coating has been UV-cured. 
     
     
       19. A conveyor according to  claim 11 , wherein the coating has a thickness of about 0.001 to about 2 mm. 
     
     
       20. A conveyor according to  claim 11 , wherein the coating comprised a waterborne UV curable acrylate or urethane or a blend or copolymer thereof, together with a lubricant comprising polytetrafluoroethylene particles. 
     
     
       21. A conveyor according to claims  12 , wherein the coating comprises about 50 to about 97 wt. % film former and about 3 wt. % to about 50 wt. % lubricant. 
     
     
       22. A conveyor according to  claim 12 , wherein the coating comprises about 70 to about 95 wt. % film former and about 5 wt. % to about 30 wt. % lubricant.